Manufacture of yarns containing staple fiber from yarns composed of continuous filaments



D 1 D. FINLAYSON ET AL 2.197.857

MANUFACTURE OF YARNS CONTAINING STAPLE FIBER FROM YARNS COMPOSED 0FCONTINUOUS FILAMENTS Original Filed Feb. 4, 1937 H6. F/G 2 u FJNLAYSON LL ATHAM INYENTOKS Y W ATTORNEYS Patented Apr. 23, 1940 UNITED STATESPATENT OFFICE MANUFACTURE OF YARNS CONTAINING STAPLE FIBER FROM YARNSCOMPOSED OF CONTINUOUS FILAMENTS Donald Finlayson and Leonard Latham,Spondon,

near Derby, England, assignors to Celanese Gorporation of America, acorporation of Delaware February 12, 1936 i 4 Claims.

This invention relates to the manufacture of yarns containing staplefibers from yarns composed of continuous filaments, and is divided fromapplication No. 124,048 for improvements in the Manufacture of yarnscontaining stable fibers from yarns composed of continuous filaments,filed February 4, 1937;

According to the present invention yarns containing staple fibers areproduced by continuously drawing yarns composed of continuous filaments,for example yarns of cellulose acetate artificial silk or the like, overa razor edge in such a way that at intervals along the yarn, some butnot all of the filaments are severed. Besides the yarns composed ofcontinuous filaments of cellulose acetate referred to above, yarnscontaining continuous filaments of other materials may also be used forthe purpose of the invention, for example materials having a, basis ofother organic derivatives of cellulose, regenerated cellulosicmaterials, for example cuprammonium artificial silk and viscoseartificial silk, and natural silk.

The yarns treated should preferably be lightly twisted but evenuntwisted yarns may be used provided that suitable means are adopted tomaintain the necessary coherence between the severed and the unseveredfilaments, for example by sizing or by the insertion during winding oftwist which runs back from the collecting device as far, or nearly asfar, as-the razor edge. On the other hand it is of advantages that thefilaments in the yarn should not be so closely packed as to prevent themfrom spreading somewhat during the severing.

The invention is particularly advantageous when applied to continuousfilament yarns whose volume or bulk has been increased, e. g., bysubjecting the yarn, either on its way to the razor edge or in aprevious stage, to a false twisting operation in the course of which thetwist inserted in the yarn is set, e. g., by the application of wetsteam or other setting agent. In the case of a false twisting operationof this kind the twist so set in the yarn automatically runs out owingto the nature of the false twisting operation. Alternatively the yarnmay, in a' previous stage, have been actually twisted prior to or duringsetting of the twist, in which case the twist should preferably beremoved. Indeed, in the case either of a twisting or of a false twistingoperation carred out in a previous stage a small quantity of twist inthe reverse direction to that set in the yarn may conveniently beimparted to the yarn after the setting and removal of twist.

In the case either of a twisting or of a false twist operation, thesetting and removal of twist leaves the yarn with a greater bulk than itpreviously possessed on account of the distortion of the individualfilaments, imposed while the yarn was temporarily twisted and retainedafter untwisting. A yarn whose bulk has been increased in this manner,and which has been given a small degree of reverse twist, isparticularly convenient for the purposes of the present invention.

One form of apparatus according to the present invention will now bedescribed in greater detail with reference to the accompanying drawing,in which:

Fig. 1 is a diagrammatic side elevation of an apparatus according to theinvention;

Fig. 2 is a front elevation of a part of Fig. 1; and

- Fig. 3 shows a detail of the apparatus shown in Figs. 1 and 2.Referring to Figs. 1 and 2, the yam l is drawn from a stationary package2 through a balloon guide 3 and then proceeds directly over an exposedpart of the edge of a, blade 4 which is of the wafer type commonlyemployed in safety razors. The blade I is provided with a guard 5 havinga gap at 6 in one of its edges through which gap the yarn is caused topass. The blade 4 and the guard 5 are secured to a holding plate I bymeans of a nut and bolt 8. The holding plate 1 is carried on a bar 9 andis set at an acute angle of, e. g., 45, to the yarn coming to it so thatthe yarn is drawn past the edge, and the filaments are not instantly andsimultaneously severed.

From the edge of the blade at the gap 8 the yarn passes through apig-tail guide Ill and thence round three rollers ll, l2, 13. The rollerI l is a driven roller and drives the rollers l2 and I3 by friction. Therollers l2 and [3 drop into slots l4 and IS in a bracket 15, the slot l4opening in front of the bracket so that the roller 12 may be dropped inin such a way that the yarn is caused to pass over the roller ll, behindthe roller l2 and in front of the roller 13. From the roller l3 the yarnproceeds to the guides ll, I8 of a take-up device by means of which theyare wound on a packa e in.

The guide In is carried on a long wire 20 which is pivotally mounted at2| on the bracket I 6. A U-shaped piece of wire 22 is secured to thewire 20' and engages with a disc 23 obliquely secured to the spindle 24of the roller I2, as is shown in Fig. 3. The obliquity of the disc. 23causes the wire 20 which is' connected to the disc 23 by the U-shapedwire 22 to oscillate about the pivot point 2| so that the pig-tail guidel0 oscillates to and fro lengthwise of the exposed edge of the blade 4.In this way the yarn is caused to traverse to and fro along the exposedpart of the blade. In order to prevent the accumulation of loose severedfilaments beneath the blade 4, a nozzle 34 is provided in order todirect a jet of air against the edge of the blade, and blow any loosefilaments away. In place of the nozzle 34 there may be employed arotating brush or a wiper which may be synchronized with thereciprocation of the thread.

When yarn having a crinkle produced by twisting the yarn, setting thetwist therein and removing the twist is employed, it is preferable thatthe take-up package l9shou1d be rotated at a speed slightly lower thanthe peripheral speed of the rollers H, l2 and I3 so that the crinkle isnot pulled out by the tension between the take-up package 19 and theroller [3.

Having described our invention, what we desire to secure byLettersPatent is:

1. Apparatus for the production of. yarn containing staple fibers fromyarns composed of continuous filaments, said apparatus comprising ablade having a razor-like cutting edge, means for continuously drawingyarns composed of continuous filaments over said edge and means fortraversing the yarn along said edge so that at intervals along the yarnsome, but not all, of the filaments are severed.

2. Apparatus for the production of yarn containing staple fibers fromyarns composed of continuous filaments, said apparatus comprising ablade having a razor-like cutting edge, means for continuously drawingyarns composed of continuous filaments over said edge, a guide forleading the filaments in contact with said edge, and means forreciprocating said guide to and fro parallel to said edge so as totraverse the yarn along said edge whereby at intervals along the yarnsome, but not all, of the filaments are severed.

3. Apparatus for the production of yarn containing staple fibers fromyarns composed of continuous filaments, said apparatus comprising ablade having a razor-like cutting edge, means for continuously drawingyarns composed of con- I tinuousfilaments over said edge, said bladebeing set so as to form an acute angle with the yarn about to cross theedge of said blade, and means for traversing the yarn along said edge sothat at intervals along the yarn some, but not all, of the filaments aresevered.

4. Apparatus for the production of yarn containing staple fibers fromyarns composed of continuous filaments, said apparatus comprising ablade having a razor-like cutting edge, a guard adapted to cover a partof said edge and means for continuously .drawing yarns composed ofcontinuous filaments over said edge so that at intervals along the yarnsome, but not all, of the filaments are severed.

DONALD FINLAYSON. LEONARD LATHAM.

